Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262178AbVD1RTu (ORCPT ); Thu, 28 Apr 2005 13:19:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262179AbVD1RTu (ORCPT ); Thu, 28 Apr 2005 13:19:50 -0400 Received: from agminet02.oracle.com ([141.146.126.229]:4217 "EHLO agminet02.oracle.com") by vger.kernel.org with ESMTP id S262178AbVD1RTr (ORCPT ); Thu, 28 Apr 2005 13:19:47 -0400 Date: Thu, 28 Apr 2005 10:19:15 -0700 From: Joel Becker To: "Stephen C. Tweedie" Cc: David Teigland , Mark Fasheh , linux-kernel , Andrew Morton Subject: Re: [PATCH 1a/7] dlm: core locking Message-ID: <20050428171915.GE4747@ca-server1.us.oracle.com> Mail-Followup-To: "Stephen C. Tweedie" , David Teigland , Mark Fasheh , linux-kernel , Andrew Morton References: <20050425165705.GA11938@redhat.com> <20050427214136.GC938@ca-server1.us.oracle.com> <20050428034550.GA10628@redhat.com> <1114696137.1920.32.camel@sisko.sctweedie.blueyonder.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1114696137.1920.32.camel@sisko.sctweedie.blueyonder.co.uk> X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. User-Agent: Mutt/1.5.9i X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1289 Lines: 35 On Thu, Apr 28, 2005 at 02:48:57PM +0100, Stephen C. Tweedie wrote: > reduce the latency for this case. My gut feeling, though, is that I'd > still prefer to see the DLM doing its work properly, cluster-wide in > this case, as precaution against accidents if we get inconsistent states > on disk leading to two nodes trying to create the same lock at once. > Experience suggests that such things *do* go wrong, and it's as well to > plan for them --- early detection is good! And unacceptably slow. With LKM_LOCAL, OCFS2 approaches ext3 speed untarring a kernel tree, because everything under the toplevel directory is a candidate for LKM_LOCAL. Network communication may be fast, but pagecache operations are even faster. I don't know by how much, but I bet if we turned off LKM_LOCAL in the OCFS2 DLM, we'd lose a lot of speed. Joel -- One look at the From: understanding has blossomed .procmailrc grows - Alexander Viro Joel Becker Senior Member of Technical Staff Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/